Fetches background images from http://gtgraphics.de/ (some of which are used in Windows 8). Organizes by resolution.

fetchBackgroundImages.php

<?php
//Fetching some of the older backgrounds requires the PHP rar extension (available through pecl). If this extension is not installed, those images will be skipped.
for($i = 1; true; $i++) {
   $tmpDir = sys_get_temp_dir();
   if(substr($tmpDir, -1) != '/') {
      $tmpDir .= '/';
   }
   if(file_exists($tmpDir.'imageList'.$i)) {
      $imageListPage = file_get_contents($tmpDir.'imageList'.$i);
   } else {
      $imageListPage = file_get_contents('http://gtgraphics.de/category/wallpapers/'.$i.'/');
      file_put_contents($tmpDir.'imageList'.$i, $imageListPage);
   }
   if(strpos($imageListPage, 'Page '.$i.'</title>') === false) {
      break;
   }
   print 'Fetched page list '.$i."\n";
   preg_match_all('#href="(http://gtgraphics.de/image/.+?)"#', $imageListPage, $matches, PREG_SET_ORDER);
   for($j = 0; $j < count($matches); $j++) {
      $url = $matches[$j][1];
      if(file_exists($tmpDir.md5($url))) {
         $imagePage = file_get_contents($tmpDir.md5($url));
      } else {
         $imagePage = file_get_contents($url);
         file_put_contents($tmpDir.md5($url), $imagePage);
      }
      print 'Fetched image page '.($j+1).'/'.count($matches);
      preg_match_all('#href="(http://gtgraphics.de/(.+?.jpg))"\>(\d+x\d+)#', $imagePage, $imageMatches, PREG_SET_ORDER);
      for($k = 0; $k < count($imageMatches); $k++) {
         @mkdir('./images/'.$imageMatches[$k][3]);
         $dest = './images/'.$imageMatches[$k][3].'/'.$imageMatches[$k][2];
         if(!file_exists($dest)) {
            file_put_contents($dest, file_get_contents($imageMatches[$k][1]));
         }
         print ' '.$imageMatches[$k][3];
      }
      if(function_exists('rar_open')) {
         preg_match('# href="(http://gtgraphics.de/(.+?\.rar).*?)"#', $imagePage, $imageMatch);
         if($imageMatch) {
            $dest = $tmpDir.$imageMatch[2];
            if(!file_exists($dest)) {
               file_put_contents($dest, file_get_contents($imageMatch[1]));
            }
            $archive = @RarArchive::open($dest);
            if($archive !== FALSE) {
               $archive->setAllowBroken(true);
               foreach($archive->getEntries() as $entry)
               {
                  $name = $entry->getName();
                  if(substr($name, -4) != '.jpg') {
                     continue;
                  }
                  $entry->extract(null, $tmpDir.'tmp.jpg');
                  $size = getimagesize($tmpDir.'tmp.jpg');
                  $imageDest = './images/'.$size[0].'x'.$size[1].'/'.$nameMatch[1];
                  if(!file_exists($imageDest)) {
                     $entry->extract(null, $imageDest);
                  }
                  print ' '.$size[0].'x'.$size[1];
               }
               $archive->close();
            } else {
               print ' BROKEN ARCHIVE';
            }
         }
      }
      print "\n";
   }
}